CONFIG_FPU is not available for thedefaultarchitecture x86.
Result is shown for architecture mn10300

FPU present

modulename: fpu.ko

configname: CONFIG_FPU

Linux Kernel Configuration
└─>Panasonic MN10300 system setup
└─>FPU present
In linux kernel since version 2.6.12  
source code:
arch/mn10300/kernel/